When spliting edge with self loop, the split edge should be placed just next to
the edge_in->src, otherwise it may generate different position latch bbs for
two consecutive self loops. For details, please refer to:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93680#c4
Regression tested pass on x86_64-linux-gnu and aarch64-linux-gnu, OK for
master?
gcc/ChangeLog:
PR gcov/93680
* tree-cfg.cc (split_edge_bb_loc): Return edge_in->src for self loop.
gcc/testsuite/ChangeLog:
PR gcov/93680
* gcc.misc-tests/gcov-pr93680.c: New test.
Signed-off-by: Xionghu Luo <xionghu...@tencent.com>
---
gcc/testsuite/gcc.misc-tests/gcov-pr93680.c | 24 +++++++++++++++++++++
gcc/tree-cfg.cc | 2 +-
2 files changed, 25 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-pr93680.c
diff --git a/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c
b/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c
new file mode 100644
index 00000000000..b2bf9e626fc
--- /dev/null
+++ b/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c
@@ -0,0 +1,24 @@
+/* { dg-options "-fprofile-arcs -ftest-coverage" } */
+/* { dg-do run { target native } } */
+
+int f(int s, int n)
+{
+ int p = 0;
+
+ switch (s)
+ {
+ case 0: /* count(5) */
+ do { p++; } while (--n); /* count(5) */
+ return p; /* count(1) */
+
+ case 1: /* count(5) */
+ do { p++; } while (--n); /* count(5) */
+ return p; /* count(1) */
+ }
+
+ return 0;
+}
+
+int main() { f(0, 5); f(1, 5); return 0; }
+
+/* { dg-final { run-gcov gcov-pr93680.c } } */
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index a9fcc7fd050..6fa1d83d366 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -3009,7 +3009,7 @@ split_edge_bb_loc (edge edge_in)
if (dest_prev)
{
edge e = find_edge (dest_prev, dest);
- if (e && !(e->flags & EDGE_COMPLEX))
+ if ((e && !(e->flags & EDGE_COMPLEX)) || edge_in->src == edge_in->dest)
return edge_in->src;
}
return dest_prev;
--
2.27.0
